Gary Lewis Posted August 7, 2019 Share Posted August 7, 2019 I did, but when I installed that one in 1995, I didn't know what the EFI 460s had, just knew that the pre-1972 set was straight up and could be bought with a steel cam gear. Someone mentioned a "Tin Indian" earlier, Pontiac V8s had no provision for lubing the timing chain. I had a guy I worked with had a 1972 LeMans with a 350 Pontiac engine, about every 3 years I put a nice steel gear set in it, the last time, when I opened it up, the chain looked very dry, so I took a page from Oldsmobile's book, drilled a 1/16" hole in the lifter gallery plug on the right bank so it would spray oil at the slack side of the chain. Never put another one in it, 6 years later when the TH350 quit for the 4th time, engine still ran great. BTW, loved their timing cover to oil pan joint, cut at a 45° angle so it was easy to seal. For you guys who mentioned the 460 water pump plate, see what happens on a Pontiac if you leave the two plates and the inlet tubes out. I mentioned the Tin Indian. Didn't know their timing sets were dry. Makes no sense! As for a 460 water pump plate, what happens when you leave one off on a serpentine system? Link to comment Share on other sites More sharing options...
85lebaront2 Posted August 7, 2019 Share Posted August 7, 2019 I mentioned the Tin Indian. Didn't know their timing sets were dry. Makes no sense! As for a 460 water pump plate, what happens when you leave one off on a serpentine system? I believe you already know the answer to that one. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2019 Share Posted August 7, 2019 I believe you already know the answer to that one. Yup. The serp bracket breaks. You nailed that one. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 7, 2019 Share Posted August 7, 2019 Right - The total weight of the balancer doesn't matter. It is the imbalance that matters as it has to negate the imbalance of the engine. So both the balancer and the flywheel are out of balance to compensate. I'll bet that yours is correctly balanced/imbalanced, but just weighs more than the other one. So, it's just like adding another pound of flywheel? I'm glad 460's have a separate hatchet weight and harmonic damper. (well, except for the pre-'79 ones that have just a spacer because they're internally balanced) How could the 460 water pump work without a backing plate? Wouldn't it just churn coolant around in the cavities of the timing cover until it found its way into the sump? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2019 Share Posted August 7, 2019 So, it's just like adding another pound of flywheel? Yep. Assuming the "imbalance" is correct the balancer or flywheel can be any weight. How could the 460 water pump work without a backing plate? Wouldn't it just churn coolant around in the cavities of the timing cover until it found its way into the sump? Huck's 460 had no backing plate. When we, you/Bill/I, were discussing the disassembly at the time I pointed out that the serp bracket was broken. Bill quickly suggested that I check for a backing plate on the water pump - and there was none. But I'm told the engine ran fine, and there was no water in the coolant. So apparently the water pump works, but probably not very well. Link to comment Share on other sites More sharing options...
85lebaront2 Posted August 7, 2019 Share Posted August 7, 2019 So, it's just like adding another pound of flywheel? I'm glad 460's have a separate hatchet weight and harmonic damper. (well, except for the pre-'79 ones that have just a spacer because they're internally balanced) How could the 460 water pump work without a backing plate? Wouldn't it just churn coolant around in the cavities of the timing cover until it found its way into the sump? Jim, it depends on the timing cover casting. If the hole that is behind the upper part of the backing plate and connects to the lifter area is not there, then it should work fairly well. I wouldn't want to chance it with a high heat load through. I was looking to see if I had a diagram of the Pontiac water pump/timing cover but they were discontinued prior to 1982 where my AllData starts. I seem to remember now that it was a single plate and the tubes with seals. The lower hose connects to a cast inlet nipple on the left side of the timing cover right where the left side inlet tube goes and the bypass passage is in the top of that cavity. Without the backing plate the pump impeller just spins the water around with no way of even directing the flow. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2019 Share Posted August 7, 2019 Jim, it depends on the timing cover casting. If the hole that is behind the upper part of the backing plate and connects to the lifter area is not there, then it should work fairly well. I wouldn't want to chance it with a high heat load through. I was looking to see if I had a diagram of the Pontiac water pump/timing cover but they were discontinued prior to 1982 where my AllData starts. I seem to remember now that it was a single plate and the tubes with seals. The lower hose connects to a cast inlet nipple on the left side of the timing cover right where the left side inlet tube goes and the bypass passage is in the top of that cavity. Without the backing plate the pump impeller just spins the water around with no way of even directing the flow. For those with curious minds, I'll take a pick of Huck's engine later this morn and post it so you can see how the backless-pump would work. (Does "curious minds" mean that particular mind is a curious thing? Did it come from Abby Normal?) Link to comment Share on other sites More sharing options...
85lebaront2 Posted August 7, 2019 Share Posted August 7, 2019 For those with curious minds, I'll take a pick of Huck's engine later this morn and post it so you can see how the backless-pump would work. (Does "curious minds" mean that particular mind is a curious thing? Did it come from Abby Normal?) At least you didn't say "inquiring minds". Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2019 Share Posted August 7, 2019 At least you didn't say "inquiring minds". Sorry for hijacking the thread (that's an emoticon we need!), but ..... At least you didn't say "inquiring minds". I think that's a more apt description. Thanks, I'll start using that terminology. Here's Huck's timing cover. And as you can see there's no place for the coolant to go but into the cooling system. Probably not as efficiently w/o a backing plate on the pump, but it would work. Link to comment Share on other sites More sharing options...
reamer Posted August 7, 2019 Author Share Posted August 7, 2019 Sorry for hijacking the thread (that's an emoticon we need!), but ..... At least you didn't say "inquiring minds". I think that's a more apt description. Thanks, I'll start using that terminology. Here's Huck's timing cover. And as you can see there's no place for the coolant to go but into the cooling system. Probably not as efficiently w/o a backing plate on the pump, but it would work. The Comp-cam double roller set-up will be here tomorrow morning. So the Build begins tomorrow morning, Leaving dounuts in the parking lot in the afternoon... Link to comment Share on other sites More sharing options...
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